Fuel injector



Dec. 2, 1947. R. LARSON ET AL FUEL INJECTOR Filed April 27, 1945 M M M r m 2 a 9, a M5 u WW 3 9% w m .|& W .26 /6 a m 2 422m f A rising from the top of the plate 5.

Patented Dec. 2, 1947 FUEL INJECTOR Raymond W. Larson, Gary, Ind., and Carl J. Stalvey, Jacksonville, Fla.

Application April 27, 1945, Serial No. 590,700 2 Claims. (01.103-50) The present invention relates to new and useful improvements in fuel injectors for all types of internal combustion engines, and has for its primary object to provide means for utilizing the compression created in the engine cylinders for operating the injector.

A further object of the invention is to provide a fuel injector or pump of this character involv- The feed pipe i1 is formed with a valve seat I8 with which a check valve I9 is engaged and yieldably maintained in closed position by a coil spring 20 positioned behind the valve.

The passage I is formed with a laterally extending cylinder 2| in which a piston 22 has a ing few working parts, whereby to reduce wear to a minimum and thus prolong the life of the device.

A further object of the invention is to provide a device of this character which requires no mechanical connections with the engine and which operates solely through the compression of the cylinders.

A still further object is to provide a device of this character of simple and practical construction, which is efficient and reliable in operation, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the drawing forming part hereof, wherein like numerals refer to like parts throughout, and in which;

Figure 1 is a side elevational view. Figure 2 is an enlarged vertical sectional view. Referring now to the drawing in detail, wherein for the purpose of illustration we have disclosed a preferred embodiment of the invention,

the numeral 5 designates an attaching plate having bolt openings 6 formed therein and by means of which the plate may be attached in a suitable position to an engine cylinder head, as indicated at 'l.

A tube 8 is threaded'in the bottom of the plate 5 for projecting into the cylinder of the engine, the tube having a pair of vertically extending passages 9 and 10 formed therein, the passage l0 being of an increased diameter.

The upper portion of the passage 9 communicates with a chamber ll having a check valve l2 mounted in its upper portion and under which is positioned a coil spring I3.

The upperendof the valve, I2 is adapted to engage a valve seat It formed at the lower end of a fuel feed passage l5 formed in .a body I6 struction (not shown).

der 2i, the tension of the spring being adjusted by means of a screw 24 threaded into the passage ii at one side of the body l6 and secured in adjusted position by a lock nut 25.

The outer end of the piston 22 is formed with a relatively large head or piston 26-working in a cylinder 21 formed in the body l6.

A passage 28 formed in the body l6 provides communication between the passage ID of the tube 8 and the cylinder 21 behind the piston 26.

A bleed port 29 communicates with the cylinder 21 adjacent its inner end and behind the piston 26.

The passage 28 communicates with the cylinder 21 by means of a neck 3|] on which a cap 3| is threaded and in which is slidably mounted a shaft 32 forming a stop at its inner end for'the piston 26.

The outer end of the shaft 32 is formed with rack teeth 33 engaging a pinion 34 adapted for manual operation to adjust the shaft 32 to limit the stroke of the pistons 22 and 26.

In the operation of the device, fuel is admitted to the injector by way of the pipe l1 and is adapted to travel past the check valve l9 into the passage IS, the spring 20 being of a tension slight- 1y less than the pressure of the fuel supplied to the injector by the usual fuel .pump.

Upon the operation of the piston in the engine cylinder into which the tube 9 projects, the pressure created in the cylinder during its. compression stroke will enter the passage l0 and pass into the passage 28 behind the piston 26 whereby to force the pistons 22 and 26 inwardly in thecylinder 2| and force the fluid from the passage l5 downwardly past the check valve l4 into the passage 9 for feeding to the engine cylinder. The passage 10 being larger than the passage 9 and the diameter of the piston 26 being greater than that of the valve M, a relatively greater pressure from the engine cylinder will be exerted on the piston 26 to thus force the valve ll open.

It is believed that the details of construction, manner of use and advantages of the device will be readily understood from the foregoing with-' out further detailed explanation.

It is to be unerstood, however, that even though we have herein shown and described a preferred embodiment of our invention that the same is susceptible of certain changes fully comprehended by the spirit of the invention as herein described, and the scope of the appended claims.

Having thus described the invention, what we claim is:

1. A fuel injector having a pain of passages therein, one of said passages constituting a fuel passage, check valves at spaced intervals in the fuel passage, a pump cylinder extending in a direction normal to the longitudinal axis of the fuel passage communicating at one end with the fuel passage between the valves and communicating at its other end with the other of said passages, said second passage being adapted to conduct pressure, a piston working in the pump cylinder and including an enlarged head responsive to the pressure in said second passage to operate the pump piston to pump fuel from the fuel passage, spring means in the pump cylinder and extending through said fuel passage diametrically from one side to the opposite side of the same and exerting its influence on the pump piston during its return stroke, and means for centering said spring and adjusting the tension thereof at the opposite side of the fuel passage and accessible exteriorly to that side;

2. A fuel injector having a pair of Passages therein, one of said passages constituting a fuel passage, check valves at spaced intervals in the fuel passage, a pump cylinder extending in a direction normal to the longitudinal axis of the fuel passage communicating at one endwith the fuel passage between the valves and communicating at its other end with the other of said passages, this second passage being adapted to conduct pressure, a piston working in the pump cylinder and including an enlarged head responsive to the pressure in said second passage to operate the pump piston to pump fuel from the fuel passage, spring means in the pump cylinder and extending transversely through said fuel passage diametrically opposite the same and exerting its influence on the pump piston during its return stroke, means for centering said spring and adjusting the tension thereof at the opposite side of the fuel passage and accessible exteriorly of that side, and an adjustable stop in the path of the pump piston to limit its return stroke, said spring tension adjusting means and stop being located on opposite sides of the injector.

' RAYMOND W. LARSON. CARL J. STALVEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

